Best-fit slab model parameters for the average VLMS spectrum (left circles) and T Tauri spectrum (right squares) for the different molecules. The H₂O component for the T Tauri spectrum is the intermediate (T ~ 600) component. Temperature and column density are shown at the top on the left and right, respectively. The equivalent emitting radius is shown in the bottom left corner, and this radius normalized to the H₂O snowline for each subsample is shown in the bottom right corner. Only the optically thick C₂H₂ component is shown for the VLMS in the radii plots because the radius is unconstrained in the optically thin case. The error bars were determined from the 1σ confidence intervals and in some cases are degenerate between parameters. For example, in the case of optically thin emission, the column density and equivalent emitting radii are degenerate. See Figures B.1 and B.2 for the χ² maps for the T Tauri and VLMS fits, respectively.